A Tip-Gap Meshing like Bilayer SERS Substrate for Highly Sensitive Detection
Abstract
Tips of noble metallic nanostructures and the gaps between closely packed noble metallic nanostructures are widely claimed as hot-spots for SERS sensing. A significant amount of effort and expertise have devoted into reformation and maximum utilization of the “tips” and “gaps”. However, most studies focus on the “tips” or the “gaps” separately. Here we report a novel SERS substrate that contains a particular meshing structure of curved-edged golden nanocubes (CENCs) and Au nanospheres (Au NSs), one of the tips of CENCs inserted into the gaps between three closely packed Au NSs. Meanwhile, a facile and time-saving novel protocol has been proposed to fabricate this meshing structure in the form of bilayer SERS substrate. The as-fabricated substrate exhibited extraordinary SERS sensitivity for malachite green (MG) and melamine attribute to the tip-gap meshing structure. The detection limit is as low as 10-12 M and 10-9 M, respectively.